QtQml: Unregister QML animation timer on deletion

The QUnifiedTimer generally outlives the QML animation timer and needs
to be notified about that latter's deletion. Otherwise it will hold a
dangling pointer.

Pick-to: 6.10 6.9 6.8
Fixes: QTBUG-136629
Change-Id: I52b7f2f3ae716128e4acac628ea29477fc17b677
Reviewed-by: Sami Shalayel <sami.shalayel@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/qml/animations/qabstractanimationjob.cpp

@@ -57,6 +57,8 @@ QQmlAnimationTimer::~QQmlAnimationTimer()
         unsetJobTimer(animation);
     for (const auto &animation : std::as_const(runningPauseAnimations))
         unsetJobTimer(animation);
+
+    QUnifiedTimer::stopAnimationTimer(this);
 }
 
 QQmlAnimationTimer *QQmlAnimationTimer::instance(bool create)

tests/auto/qml/animation/qabstractanimationjob/tst_qabstractanimationjob.cpp

@@ -1,10 +1,12 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
+#include <QtQml/qqmlengine.h>
+#include <QtTest/qtest.h>
 
-#include <QtQml/private/qabstractanimationjob_p.h>
-#include <QtQml/private/qanimationgroupjob_p.h>
-#include <QTest>
+#include <private/qabstractanimationjob_p.h>
+#include <private/qanimationgroupjob_p.h>
+#include <private/qcoreapplication_p.h>
 
 class tst_QAbstractAnimationJob : public QObject
 {
@@ -23,6 +25,7 @@ private slots:
     void avoidJumpAtStart();
     void avoidJumpAtStartWithStop();
     void avoidJumpAtStartWithRunning();
+    void deleteAnimationTimer();
 };
 
 class TestableQAbstractAnimation : public QAbstractAnimationJob
@@ -184,6 +187,24 @@ void tst_QAbstractAnimationJob::avoidJumpAtStartWithRunning()
     QVERIFY(anim3.currentTime() < 50);
 }
 
+void tst_QAbstractAnimationJob::deleteAnimationTimer()
+{
+    for (int i = 0; i < 10; ++i) {
+        {
+            TestableQAbstractAnimation mainAnimation;
+            mainAnimation.setDuration(100);
+            mainAnimation.start();
+            QTRY_VERIFY(mainAnimation.isRunning());
+            QTRY_VERIFY(mainAnimation.currentTime() > 50);
+        }
+
+        // We can tear down the thread data that holds the animation timer. This does not cause
+        // the QUnifiedTimer to hold a dangling pointer next timer around.
+        static_cast<QCoreApplicationPrivate *>(QObjectPrivate::get(QCoreApplication::instance()))
+                ->cleanupThreadData();
+    }
+}
+
 
 QTEST_MAIN(tst_QAbstractAnimationJob)